Sean Kingston just picked up another L … and it wasn’t cheap. The rapper’s been ordered to pay $301,500 to NYC jeweler Aqua Master who sued him over 9 pieces of jewelry but was never paid. The items included 2 diamond necklaces, a few gold chains, a ring and 2 watches.

Making matters worse, Aqua says Sean flaunted the pieces on his IG

TMZ broke the story … Aqua sued Sean back in 2016, but the rapper never responded to the lawsuit, so the judge issued a default judgment. Aqua says Sean made a halfhearted attempt to pay … sending 2 checks. But they later bounced.

Sean’s got issues with jewelers over the years. He was sued in Florida and had already been ordered to pay another jeweler in 2015.